Adsorption
and reaction of N2H4 and NH3 on powdered TiO2 have been studied by Fourier-transformed
infrared spectroscopy. N2H4 decomposes on the surface to form NH3 and surface hydroxy groups at temperatures
higher than ∽150°C. Based on these findings, a N2H4
reaction pathway on TiO2
is established to be N2H4→2NH2→NH+NH3
and NH+O(l)→N+OH(ads). NH3 decomposes on the surface and forms adsorbed
azide N3(ads) species at temperatures higher than ∽350°C. Photooxidation of NH3 and ND3 is investigated
as well and the mechanism is discussed in terms of the NH2 reaction pathway
and recent reports for the reactions between NHx and NOx (x=1–2) in the gas phase.